chuong-3 khoi nguon nuoi

8/14/2019 Chuong-3 Khoi Nguon Nuoi

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Ch ng 3: Kh i Ngu n Nui

Bi 1: Nguyn l ho t ng c a kh i ngu n

Ni dung : Nhim vca khi ngun, S khi ngun tng qut, Tn ca cc in p khi ng vp iu khin, Tm tt qu trnh hot ng m ngun.

1 Nhi m v ca kh i ngu n Cp ngun V.BAT (Ngun Pin) cho 3 IC n dng ln l IC khuch i cng sut pht, IC ngun vIC Dung-Chung-Led.

Cc IC n dng ln c cp tr c tip ngun Pin ( V.BAT ), khi ta lp Pin vo my, ngun + Pin lptc i n cp ngun cho cc IC: K cng sut pht, IC Ngun, IC Dung-Chung-Led, tuy nhin banu cha bt ngun, cc IC ny tr ng thi cha hot ng nn chng n dng r t nh ( vi mA )

Cp ngun khi ng cho khi iu khin hot ng.

Ngun khi ng cp cho khi iu khin l ngun xut hin sau khi ta bt cng tc ON-OFF ( Cngtc tt mmy ) ngun khi ng l ngun gin tip i ra t IC ngun bao gm :


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- VK 1 : in p khi ng 1 => Cp cho bdao ng 26MHz hoc 13MHz to xung Clock choCPU .- VK 2 : in p khi ng 2 => Cp ngun cho IC Vi x l (CPU)- VK 3 : in p khi ng 3 => Cp ngun cho CPU v MemoryKhic cp ngun, khi iu khin hot ng, CPU s truy cp vo bnh FLASH ly ra phnmm iu khin mi s hot ng ca my nh - a ra lnh duy tr cc in p khi ng .- Cho php mn hnh hin th - iu khin cp ngun cho khi thu pht sng- Kim tra d liu trn SIM CardV vy nu CPU hng hay bnh FLASH hng hoc mt dao ng 13MHz th khi iu khin s khng hot ng v khng a ra c cc lnh trn => kt qu l my khng m cngun .Tr ng hp CPU v FLASH khng hng nhng li phn mm th my c thmt sng hoc khnga ra c giao din trn mn hnh .

Cp ngun cho khi thu pht sng hot ng.

l cc in p iu khin bao gm- V K1 in p iu khin 1 - Cp cho mch Thu sng- V K2 in p iu khin 2 - Cp cho mch Pht sng- V K3 in p iu khin 3 - Cp chung cho mch Thu &Pht sngKhi khi iu khin hot ng v phn mm bnh thng, CPU s a ra cc in p iu khin quayli IC Ngun iu khin m ra cc in p iu khin cung cp cho khi thu pht sng .Nu khi iu khin cha hot ng th skhng c lnh quay li iu khin IC ngun m ra cc inp trn .

2. S kh i ngu n t ng qut


3/16

Hot ng ca khi ngun .

- Khi lp Pin vo my, in p Pin ( V.BAT ) i vo cp ngun cho mt s chn ca IC ngun, lc nyIC ngun cha hot ng nhng xut hin in p a ra chn cng tc PWR-ON >0V .- Khi ta bt cng tc ngun, chn PWR-ON thay i tr ng thi t cao xung thp => Lm khi ngIC ngun => IC ngun a ra cc in p khi ng bao gm :+ VK 1 (2,8V) Cp cho mch dao ng to xung Clock 13MHz+ VK 2 (1,8V) Cp cho IC Vi x l CPU+ VK 3 (2,8V) Cp cho IC Vi x l v cc IC nh, mn hnh LCD- Bdao ng to xung Clock 13MHza vo CPU to xung nhp cho CPU hot ng .- CPU hot ng s truy cp vo Memory ly ra chng trnh phn mm duy tr lnh m ngun vcho mn hnh hin th .- CPU a ra cc lnh quay li iu khin IC ngun m ra cc in p iu khin V K1, V K2,

V K3 cp ngun cho khi thu pht sng hot ng .3. Tn c a cc in p kh i ng v p iu khi n

Vi cc my NOKIA th- VK 1 c tn l VCXO hoc VR3 : Ngun cp cho mch dao ng- VK 2 c tn l VCORE : Ngun cp cho CPU- VK 3 c tn VBB hoc VIO : Ngun cp cho CPU v Memory- V K1 c tn l V-RX hoc VR4 : in p cp cho knh thu- V K2 c tn l V-TX hoc VR2 : in p cp cho knh pht- V K3 c tn l VSYN1, VSYN2 : in p ng b cc tn hiu

Vi cc my SAMSUNG th- VK 1 c tn l XVCC- VK 2 c tn l AVCC- VK 3 c tn l VCC- V K1 c tn l V-RX in p cp cho knh thu- V K2 c tn l V-TX in p cp cho knh pht- V K3 c tn l V-MSMA, V-MSMP

Ch :


4/16

Vi my NOKIA v mt s i ca Motorola th bdao ng to ra tn s26MHz sau a quaIC cao trung tn chia i thnh 13MHz =>a vo CPU to xung Clock .

M ch dao ng 26MHz i qua IC cao t n chia i l y ra 13MHz a vo CPU

Cc my SAMSUNG to ra tn s13MHza tr c tip vo CPU - Mt s i my SAMSUNG tora tn s19,5MHz .

4. Tm t t qu trnh ho t ng m ngu n

Qu trnh hot ng m ngun tr i qua 7 bc: Bc 1 : Cp ngun V.BAT cho my Bc 2 : Xut hin in p ch chn PWR-ON Bc 3 : Sau khi bm cng tc ON-OFF IC ngun cho ra cc in p khi ng Bc 4 : Mch dao ng hot ng cung cp 13MHz cho CPU Bc 5 : CPU hot ng, khi iu khin hot ng. Bc 6 : CPU truy cp vo bnh ly ra phn mm iu khin my. Bc 7 : CPU ly c phn mm v cho lnh duy tr ngun.

Ta thy r ng nu cc bc pha tr c m hng th my khng th chuyn sang c cc bctip theo v vy. Khi sa my khng m c ngun => ta cn kh\im tra theo th t:Bc 1 => Bc 2 => Bc 3 => Bc 4 => Bc 5 => Bc 6 => Bc 7 V d - Mt bi hc xng mu.C mt ng th A thiu kinh nghim, ng ta hc mt c mt pan bnh ca ng th B khi thy ngth B np phn mm cho mt my khng ln ngun, vnh ng ta c ng np phn mm cho mt mykhng ln ngun => Kt qu l ng ta lm hng hp np phn mm v hng cng USB trn mytnh .Nguyn nhn: Do ng ta i np phn mm cho mt my b chp ngun V.BAT m khng kim tracc bc t Bc 1 n Bc 5 tr c. => Hi ra ng thA mi bit, tr c khi np phn mm (hng


5/16

Bc 6 ) ng th B kim tra r t kv my hot ng n Bc 5 Oh !!! Tht l mt bi hcxng mu. Trong bi sau s trnh by phng php kim tra ngun.

Bi 2: Ph ng Php Ki m Tra My Khng M Ngu n

Ni dung : Phng php kim tra my khng m ngun bng ng hvn nng, S dng ng h dng kim tra, Phng php kim tra ngun bng ng hdng.

1. Ph ng php ki m tra (my khng m ngu n) b ng ng h vn n ng.

Mt my khng m c ngun c thdo nhiu nguyn nhn, vic xc nh ng nguyn nhn va ra mt quy trnh kim tra hp l sgip cho bn xc nh nhanh chng cc h hng ca my.

Cc nguyn nhn lm cho my khng m ngun- My b chp ngun V.BAT- Hng mch cng tc tt m nh (Cng tc khng tip xc, lng mi hn chn cng tc)- My b m, b nc vo lm mt dao ng 13MHz cp cho CPU- Hng IC ngun khng a ra c cc in p khi ng .- Hng IC Vi x l- Hng bnh FLASH- Li phn mm .

Cc b c ki m tra:

Dng ng hvn nng, thang X1, o tr khng gia chn dng v chn m ca tip Pin .

Nu kt qu o thy:- Mt chiu o kim ln khong 2/3 thang o- o chiu ngc li kim khng ln (chiu que vo m que en vo dng - kim khng ln) =>L tr khng bnh thng .


6/16

- Chai chiu o kim ln = 0 => L my b chp ngun V.BAT.

Nguyn nhn ch p ngu n V.BAT

L do chp cc linh kin n tr c tip ngun V.BAT bao gm cc linh kin :- IC khuch i cng sut pht- IC ngun- IC Dung - Chung - LedTrong IC khuch i cng sut pht c t lhng cao nht

Ngun V.BAT cp tr c tip cho cc IC Khuch i cng sut, IC Ngun v IC Dung-Chung-Led

Kim tra khi th y ch p ngu n V.BAT:

Cch 1 - Bn lp Pin vo my khong 10 giy v kim tra nhanh bng cch t tay vo lng cc linhkin trn, nu linh kin no nng th linh kin b chp.Cch 2 - Bn c lp cc IC bng cch g cun dy lc nhiu trn ng cp ngun cho cc IC rasau kin tra tr khng ca tng IC mt .


7/16

Lu :- Trn ng V.BAT c nhiu tho lc, y l cc im gip bn o kim tra in p ngun cungcp cho IC bi v bn khng th o c tr c tip vo chn IC chn gm .- Cc tho v tgm trn in thoi ding r t t khi b chp hay b d, ch c in thoi hngSIEMENS sn xut t c l c hin tng b d t .

Kim tra cng tc ON - OFF- Bn cn kin tra chn cng tc ON-OFF xem c bong mi hnkhng ?- o kim tra xem cng tc c tip xc khi ta bm khng ?

Quan st v my xem c du hiu m, mc mch in khng? nu c l du hiu my b nc vo.- Nu v mch b m mc, bn s dng du r a mch in r a sch v my sau sy kh .

Quan st k v my xem c b m, m c khng ? Kim tra cc in p khi ng.- Tra s xc nh c cc t lc trn ng cp in p iu khin nhVCXO, VCORE,VBB.- Bt cng tc ngun v o kim tra cc in p VCXO, VCORE, VBB trn cc t lc. Nu khng c3 in p trn l hng IC ngun. Nu vn c 3 in p trn th c thdo:

- Hng CPU- Hng bnh FLASH- Li phn mm Dng hp np phn mm kt ni vi my in thoi sau bt cng tc ngun.

Nu my hin c ch Local mode trn in thoi => L khi iu khin hot ng => Tr nghp ny bn chy li phn mm l c (xem phn - Np phn mm sacha).


8/16


9/16

Vi my Samsung:Bn ch vic cm r c ngun t ng hdng vo my

Vi my NOKIAVi my Nokia bn phi u c4 tr u th my mi c thm c ngun.- Dng pin- m pin- Chn BSI - chn bo dung lng pin- Chn BTEMP - chn bo nhit pin ng hdng c 4 r c trn tuy nhin bn dng cc r c bo Pin v bo nhit t ng h dng thng khng c Vy phi lm thno ?

Nh bn thy Pin c cmt v vi mch ly ra in p BSI v BTEM, v vy nu bn dng ng h dng th khng c v vi mch trn v my khng m c ngun.=>Bn hy dng quPin hng c v vi mch cn tt v hn chn dng ng hdng vo v mchthay cho dng pin, m ng hdng thay cho m pin.


10/16

3. Ph ng php o ki m tra ngu n b ng ng h dng

Kho st dng tiu thkhi my cn tt.- Ch nh ng hdng c in p t 4 n 4,5V

- Cp ngun vo my, bt cng tc ngun trn in thoi => Quan st ng h o dng.Mt my in thoi bnh thng, khi bt m ngun s c dng tiu thnh sau :

Dng tiu th c a my bnh th ng khi ta b t cng t c - Khi cha bt cng tc ON/OFFKhi cha bt cng tc ON/OFF => dng tiu th= 0


11/16

- Sau khi bt cng tc ON/OFFSau khi bt cng tc ON/ OFF => dng tiu th tng ln khong 100mA khi mn hnh sng ln.

- Khiin thoi pht sng v tng iSau dng tiu th tng ln ti 150mA v dao ng ln xung l lc my pht sng gi tn hiuiu khin v tng i .

- Sau khi kt thc qu trnh pht sng. Sau khi pht sng v tng i kt thc, dng tiu th gim xung 50mA , lc ny my vn cn mn hnh sng.


12/16

- Khi my chuyn sang ch ch, dng tiu thgim thp.Sau khong 1 n 2 pht tu theo thit lp, my chuyn sang ch ch, mn hnh ti v ch hin th ng h thi gian, lc ny dng tiu thch khong 20mA

Biu hi n c a my b ch p ngu n V.BAT.- Bn va mi cp ngun vo my cha kp bt cng tc thy kimng hdng tng vt => Sau ng hdng ct in p ra => kim tr v0 .

ng h dng t ng v t khi m i c p i n cho i n tho i => M t bi u hi n c a ch p ngu n V.BAT

Biu hi n c a my b d ngu n V.BAT Nu bn mi cp ngun cho my, bn cha bt cng tc nhng thy my tiu thdng => lbiu hin ca my b d ngun V.BAT =>> Tr ng hp ny mt smy vn hot ng nhng r tnhanh ht Pin.


13/16

My tiu th dng khi ta ch a b t cng t c ngu n => Bi u hi n c a my b d ngu n V.BAT

Bi 3: B ngu n r i r c my Samsung

Ni dung : S khi tng qut, Nguyn l hot ng cangun r i r c.

B ngu n r i r c (khng s dng IC ngun) Ngun r i r c c s dng trn my Samsung Khng dng IC ngun m dng cc n bn dn kp 5 chn iu khin: M, Chia v n nhngun.

1. S kh i tng qut

S t ng qut kh i ngu n s d ng n kp trong cc my SAMSUNG


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15/16

Khi ta bm phm ON/OFF =>in p i qua cng tc => qua Diode kp vo iu khin chn s3(EN) ca cc n kp, chn EN c mc cao => cho php in p i t chn IN sang chn OUT =>Cung cp cho khi iu khin cc in p khi ng bao gm:- in p V K1 (XVCC) cung cp cho mch dao ng 13MHz- in p V K2 (AVCC) cung cp cho CPU- in p V K3 (VCC) cung cp cho CPU v Memory Khi c dao ng 13MHz, CPU & FLASH tt, phn mm tt khi iu khin shot ng, CPU traoi d liu vi Memory ly ra phn mm v tip tc iu khin my thng qua cc lnh :- Lnh duy tr ngun PWR-ON- Lnh PWR-RXiu khin cp ngun cho knh pht- Lnh PWR-TXiu khin cp ngun cho knh thu . IC tng p shot ng khi ngun V.BAT b gim, nhm duy tr s hot ng ca my khi Pin yu.

V my Samsung s d ng cc n kp 5 chn v 6 chn i u khi n ngu nXc nh chn IC chn gm Trong cc in thoi hin nay, hu ht s dng cc IC chn gm:

Xc nh chn ca IC chn gm


16/16

Cch xc nh IC chn gm nh sau:Tnh theo chn trn mch in, tnh t gc c du trn th- Thun chiu kimng h l s1 - 2 - 3 - 4 - 5 ...

- Ngc chiu kimng h l A - B - C - D ...- Mt chn bt k ta ta dng sang hai pha vung gc s xc nh c chn, c ch tr c s sau.

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